Sidelink drx operation based on multiple drx configurations and prioritization

ABSTRACT

A method and apparatus for Sidelink (SL) Discontinuous Reception (DRX) operation based on multiple DRX configurations and prioritization is provided. A third wireless device receives, from a first wireless device, first Sidelink (SL) Discontinuous Reception (DRX) information, and receives, from a second wireless device, second SL DRX information. The third wireless device informs a network about the first and second SL DRX information, each of which is constructed for each pair of source and destination.

TECHNICAL FIELD

The present disclosure relates to Sidelink (SL) Discontinuous Reception(DRX) operation based on multiple DRX configurations and prioritization.

BACKGROUND

3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is atechnology for enabling high-speed packet communications. Many schemeshave been proposed for the LTE objective including those that aim toreduce user and provider costs, improve service quality, and expand andimprove coverage and system capacity. The 3GPP LTE requires reduced costper bit, increased service availability, flexible use of a frequencyband, a simple structure, an open interface, and adequate powerconsumption of a terminal as an upper-level requirement.

Work has started in International Telecommunication Union (ITU) and 3GPPto develop requirements and specifications for New Radio (NR) systems.3GPP has to identify and develop the technology components needed forsuccessfully standardizing the new RAT timely satisfying both the urgentmarket needs, and the more long-term requirements set forth by the ITURadio communication sector (ITU-R) International MobileTelecommunications (IMT)-2020 process. Further, the NR should be able touse any spectrum band ranging at least up to 100 GHz that may be madeavailable for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usagescenarios, requirements and deployment scenarios including enhancedMobile BroadBand (eMBB), massive Machine Type Communications (mMTC),Ultra-Reliable and Low Latency Communications (URLLC), etc. The NR shallbe inherently forward compatible.

Vehicle-to-everything (V2X) communication is the passing of informationfrom a vehicle to any entity that may affect the vehicle, and viceversa. It is a vehicular communication system that incorporates othermore specific types of communication as Vehicle-to-Infrastructure (V2I),Vehicle-to-Network (V2N), Vehicle-to-Vehicle (V2V),Vehicle-to-Pedestrian (V2P), Vehicle-to-Device (V2D) and Vehicle-to-Grid(V2G).

SUMMARY

The present disclosure provides a method and apparatus for informing anetwork of SL DRX information received from other wireless devices, eachof which is constructed for each pair of source and destination.

In an aspect, a method performed by a third wireless device operating ina wireless communication system is provided. The method includesreceiving, from a first wireless device, first Sidelink (SL)Discontinuous Reception (DRX) information, receiving, from a secondwireless device, second SL DRX information, and informing a networkabout the first and second SL DRX information, each of which isconstructed for each pair of source and destination.

In another aspect, a method performed by a network node device operatingin a wireless communication system is provided. The method includesreceiving, from a wireless device, first DRX information and second SLDRX information, each of which is constructed for each pair of sourceand destination.

In another aspect, apparatuses for implementing the above method isprovided.

The present disclosure can have various advantageous effects.

For example, DL DRX and SL DRX can be aligned by enabling UE performingSL transmission/reception to report SL DRX information of other UE tothe network.

For example, UE performing reception on a pool of resources can save UEpower, in particular when UE receive multiple DRX configurations fromother UE(s) and/or the network.

For example, the system can properly provide power-efficient sidelinkreception based on multiple DRX configurations and prioritization.

Advantageous effects which can be obtained through specific embodimentsof the present disclosure are not limited to the advantageous effectslisted above. For example, there may be a variety of technical effectsthat a person having ordinary skill in the related art can understandand/or derive from the present disclosure. Accordingly, the specificeffects of the present disclosure are not limited to those explicitlydescribed herein, but may include various effects that may be understoodor derived from the technical features of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a communication system to whichimplementations of the present disclosure is applied.

FIG. 2 shows an example of wireless devices to which implementations ofthe present disclosure is applied.

FIG. 3 shows an example of a wireless device to which implementations ofthe present disclosure is applied.

FIG. 4 shows an example of UE to which implementations of the presentdisclosure is applied.

FIGS. 5 and 6 show an example of protocol stacks in a 3GPP basedwireless communication system to which implementations of the presentdisclosure is applied.

FIG. 7 shows a frame structure in a 3GPP based wireless communicationsystem to which implementations of the present disclosure is applied.

FIG. 8 shows a data flow example in the 3GPP NR system to whichimplementations of the present disclosure is applied.

FIG. 9 shows an example of NG-RAN architecture supporting PC5 interfaceto which implementations of the present disclosure is applied.

FIG. 10 shows an example of a method performed by a third wirelessdevice to which implementation of the present disclosure is applied.

FIG. 11 shows an example of a method performed by a network node towhich implementation of the present disclosure is applied.

FIGS. 12 and 13 shows an example of sidelink transmission and sidelinkreception to which implementation of the present disclosure is applied.

DETAILED DESCRIPTION

The following techniques, apparatuses, and systems may be applied to avariety of wireless multiple access systems. Examples of the multipleaccess systems include a Code Division Multiple Access (CDMA) system, aFrequency Division Multiple Access (FDMA) system, a Time DivisionMultiple Access (TDMA) system, an Orthogonal Frequency Division MultipleAccess (OFDMA) system, a Single Carrier Frequency Division MultipleAccess (SC-FDMA) system, and a Multi Carrier Frequency Division MultipleAccess (MC-FDMA) system. CDMA may be embodied through radio technologysuch as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA maybe embodied through radio technology such as Global System for Mobilecommunications (GSM), General Packet Radio Service (GPRS), or EnhancedData rates for GSM Evolution (EDGE). OFDMA may be embodied through radiotechnology such as Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA(E-UTRA). UTRA is a part of a Universal Mobile Telecommunications System(UMTS). 3rd Generation Partnership Project (3GPP) Long-Term Evolution(LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employsOFDMA in downlink (DL) and SC-FDMA in uplink (UL). Evolution of 3GPP LTEincludes LTE-Advanced (LTE-A), LTE-A Pro, and/or 5G New Radio (NR).

For convenience of description, implementations of the presentdisclosure are mainly described in regards to a 3GPP based wirelesscommunication system. However, the technical features of the presentdisclosure are not limited thereto. For example, although the followingdetailed description is given based on a mobile communication systemcorresponding to a 3GPP based wireless communication system, aspects ofthe present disclosure that are not limited to 3GPP based wirelesscommunication system are applicable to other mobile communicationsystems.

For terms and technologies which are not specifically described amongthe terms of and technologies employed in the present disclosure, thewireless communication standard documents published before the presentdisclosure may be referenced.

In the present disclosure, “A or B” may mean “only A”, “only B”, or“both A and B”. In other words, “A or B” in the present disclosure maybe interpreted as “A and/or B”. For example, “A, B or C” in the presentdisclosure may mean “only A”, “only B”, “only C”, or “any combination ofA, B and C”.

In the present disclosure, slash (/) or comma (,) may mean “and/or”. Forexample, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “onlyA”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, Bor C”.

In the present disclosure, “at least one of A and B” may mean “only A”,“only B” or “both A and B”. In addition, the expression “at least one ofA or B” or “at least one of A and/or B” in the present disclosure may beinterpreted as same as “at least one of A and B”.

In addition, in the present disclosure, “at least one of A, B and C” maymean “only A”, “only B”, “only C”, or “any combination of A, B and C”.In addition, “at least one of A, B or C” or “at least one of A, B and/orC” may mean “at least one of A, B and C”.

Also, parentheses used in the present disclosure may mean “for example”.In detail, when it is shown as “control information (PDCCH)”, “PDCCH”may be proposed as an example of “control information”. In other words,“control information” in the present disclosure is not limited to“PDCCH”, and “PDDCH” may be proposed as an example of “controlinformation”. In addition, even when shown as “control information(i.e., PDCCH)”, “PDCCH” may be proposed as an example of “controlinformation”.

Technical features that are separately described in one drawing in thepresent disclosure may be implemented separately or simultaneously.

Although not limited thereto, various descriptions, functions,procedures, suggestions, methods and/or operational flowcharts of thepresent disclosure disclosed herein can be applied to various fieldsrequiring wireless communication and/or connection (e.g., 5G) betweendevices.

Hereinafter, the present disclosure will be described in more detailwith reference to drawings. The same reference numerals in the followingdrawings and/or descriptions may refer to the same and/or correspondinghardware blocks, software blocks, and/or functional blocks unlessotherwise indicated.

FIG. 1 shows an example of a communication system to whichimplementations of the present disclosure is applied.

The 5G usage scenarios shown in FIG. 1 are only exemplary, and thetechnical features of the present disclosure can be applied to other 5Gusage scenarios which are not shown in FIG. 1 .

Three main requirement categories for 5G include (1) a category ofenhanced Mobile BroadBand (eMBB), (2) a category of massive Machine TypeCommunication (mMTC), and (3) a category of Ultra-Reliable and LowLatency Communications (URLLC).

Referring to FIG. 1 , the communication system 1 includes wirelessdevices 100 a to 100 f, Base Stations (BSs) 200, and a network 300.Although FIG. 1 illustrates a 5G network as an example of the network ofthe communication system 1, the implementations of the presentdisclosure are not limited to the 5G system, and can be applied to thefuture communication system beyond the 5G system.

The BSs 200 and the network 300 may be implemented as wireless devicesand a specific wireless device may operate as a BS/network node withrespect to other wireless devices.

The wireless devices 100 a to 100 f represent devices performingcommunication using Radio Access Technology (RAT) (e.g., 5G NR or LTE)and may be referred to as communication/radio/5G devices. The wirelessdevices 100 a to 100 f may include, without being limited to, a robot100 a, vehicles 100 b-1 and 100 b-2, an eXtended Reality (XR) device 100c, a hand-held device 100 d, a home appliance 100 e, anInternet-of-Things (IoT) device 100 f, and an Artificial Intelligence(AI) device/server 400. For example, the vehicles may include a vehiclehaving a wireless communication function, an autonomous driving vehicle,and a vehicle capable of performing communication between vehicles. Thevehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone).The XR device may include an Augmented Reality (AR)/Virtual Reality(VR)/Mixed Reality (MR) device and may be implemented in the form of aHead-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle,a television, a smartphone, a computer, a wearable device, a homeappliance device, a digital signage, a vehicle, a robot, etc. Thehand-held device may include a smartphone, a smartpad, a wearable device(e.g., a smartwatch or a smartglasses), and a computer (e.g., anotebook). The home appliance may include a TV, a refrigerator, and awashing machine. The IoT device may include a sensor and a smartmeter.

In the present disclosure, the wireless devices 100 a to 100 f may becalled User Equipments (UEs). A UE may include, for example, a cellularphone, a smartphone, a laptop computer, a digital broadcast terminal, aPersonal Digital Assistant (PDA), a Portable Multimedia Player (PMP), anavigation system, a slate Personal Computer (PC), a tablet PC, anultrabook, a vehicle, a vehicle having an autonomous traveling function,a connected car, an UAV, an AI module, a robot, an AR device, a VRdevice, an MR device, a hologram device, a public safety device, an MTCdevice, an IoT device, a medical device, a FinTech device (or afinancial device), a security device, a weather/environment device, adevice related to a 5G service, or a device related to a fourthindustrial revolution field.

The UAV may be, for example, an aircraft aviated by a wireless controlsignal without a human being onboard.

The VR device may include, for example, a device for implementing anobject or a background of the virtual world. The AR device may include,for example, a device implemented by connecting an object or abackground of the virtual world to an object or a background of the realworld. The MR device may include, for example, a device implemented bymerging an object or a background of the virtual world into an object ora background of the real world. The hologram device may include, forexample, a device for implementing a stereoscopic image of 360 degreesby recording and reproducing stereoscopic information, using aninterference phenomenon of light generated when two laser lights calledholography meet.

The public safety device may include, for example, an image relay deviceor an image device that is wearable on the body of a user.

The MTC device and the IoT device may be, for example, devices that donot require direct human intervention or manipulation. For example, theMTC device and the IoT device may include smartmeters, vending machines,thermometers, smartbulbs, door locks, or various sensors.

The medical device may be, for example, a device used for the purpose ofdiagnosing, treating, relieving, curing, or preventing disease. Forexample, the medical device may be a device used for the purpose ofdiagnosing, treating, relieving, or correcting injury or impairment. Forexample, the medical device may be a device used for the purpose ofinspecting, replacing, or modifying a structure or a function. Forexample, the medical device may be a device used for the purpose ofadjusting pregnancy. For example, the medical device may include adevice for treatment, a device for operation, a device for (in vitro)diagnosis, a hearing aid, or a device for procedure.

The security device may be, for example, a device installed to prevent adanger that may arise and to maintain safety. For example, the securitydevice may be a camera, a Closed-Circuit TV (CCTV), a recorder, or ablack box.

The FinTech device may be, for example, a device capable of providing afinancial service such as mobile payment. For example, the FinTechdevice may include a payment device or a Point of Sales (PoS) system.

The weather/environment device may include, for example, a device formonitoring or predicting a weather/environment.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR)network, and a beyond-5G network. Although the wireless devices 100 a to100 f may communicate with each other through the BSs 200/network 300,the wireless devices 100 a to 100 f may perform direct communication(e.g., sidelink communication) with each other without passing throughthe BSs 200/network 300. For example, the vehicles 100 b-1 and 100 b-2may perform direct communication (e.g., Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b and 150 c may beestablished between the wireless devices 100 a to 100 f and/or betweenwireless device 100 a to 100 f and BS 200 and/or between BSs 200.Herein, the wireless communication/connections may be establishedthrough various RATs (e.g., 5G NR) such as uplink/downlink communication150 a, sidelink communication (or Device-to-Device (D2D) communication)150 b, inter-base station communication 150 c (e.g., relay, IntegratedAccess and Backhaul (TAB)), etc. The wireless devices 100 a to 100 f andthe BSs 200/the wireless devices 100 a to 100 f may transmit/receiveradio signals to/from each other through the wirelesscommunication/connections 150 a, 150 b and 150 c. For example, thewireless communication/connections 150 a, 150 b and 150 c maytransmit/receive signals through various physical channels. To this end,at least a part of various configuration information configuringprocesses, various signal processing processes (e.g., channelencoding/decoding, modulation/demodulation, and resourcemapping/de-mapping), and resource allocating processes, fortransmitting/receiving radio signals, may be performed based on thevarious proposals of the present disclosure.

AI refers to the field of studying artificial intelligence or themethodology that can create it, and machine learning refers to the fieldof defining various problems addressed in the field of AI and the fieldof methodology to solve them. Machine learning is also defined as analgorithm that increases the performance of a task through steadyexperience on a task.

Robot means a machine that automatically processes or operates a giventask by its own ability. In particular, robots with the ability torecognize the environment and make self-determination to perform actionscan be called intelligent robots. Robots can be classified asindustrial, medical, home, military, etc., depending on the purpose orarea of use. The robot can perform a variety of physical operations,such as moving the robot joints with actuators or motors. The movablerobot also includes wheels, brakes, propellers, etc., on the drive,allowing it to drive on the ground or fly in the air.

Autonomous driving means a technology that drives on its own, andautonomous vehicles mean vehicles that drive without user's control orwith minimal user's control. For example, autonomous driving may includemaintaining lanes in motion, automatically adjusting speed such asadaptive cruise control, automatic driving along a set route, andautomatically setting a route when a destination is set. The vehiclecovers vehicles equipped with internal combustion engines, hybridvehicles equipped with internal combustion engines and electric motors,and electric vehicles equipped with electric motors, and may includetrains, motorcycles, etc., as well as cars. Autonomous vehicles can beseen as robots with autonomous driving functions.

Extended reality is collectively referred to as VR, AR, and MR. VRtechnology provides objects and backgrounds of real world only throughComputer Graphic (CG) images. AR technology provides a virtual CG imageon top of a real object image. MR technology is a CG technology thatcombines and combines virtual objects into the real world. MR technologyis similar to AR technology in that they show real and virtual objectstogether. However, there is a difference in that in AR technology,virtual objects are used as complementary forms to real objects, whilein MR technology, virtual objects and real objects are used as equalpersonalities.

NR supports multiples numerologies (and/or multiple Sub-Carrier Spacings(SCS)) to support various 5G services. For example, if SCS is 15 kHz,wide area can be supported in traditional cellular bands, and if SCS is30 kHz/60 kHz, dense-urban, lower latency, and wider carrier bandwidthcan be supported. If SCS is 60 kHz or higher, bandwidths greater than24.25 GHz can be supported to overcome phase noise.

The NR frequency band may be defined as two types of frequency range,i.e., Frequency Range 1 (FR1) and Frequency Range 2 (FR2). The numericalvalue of the frequency range may be changed. For example, the frequencyranges of the two types (FR1 and FR2) may be as shown in Table 1 below.For ease of explanation, in the frequency ranges used in the NR system,FR1 may mean “sub 6 GHz range”, FR2 may mean “above 6 GHz range,” andmay be referred to as millimeter Wave (mmW).

TABLE 1 Frequency Range Corresponding designation frequency rangeSubcarrier Spacing FR1  450 MHz-6000 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

As mentioned above, the numerical value of the frequency range of the NRsystem may be changed. For example, FR1 may include a frequency band of410 MHz to 7125 MHz as shown in Table 2 below. That is, FR1 may includea frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more. Forexample, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) ormore included in FR1 may include an unlicensed band. Unlicensed bandsmay be used for a variety of purposes, for example for communication forvehicles (e.g., autonomous driving).

TABLE 2 Frequency Range Corresponding designation frequency rangeSubcarrier Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

Here, the radio communication technologies implemented in the wirelessdevices in the present disclosure may include NarrowBand IoT (NB-IoT)technology for low-power communication as well as LTE, NR and 6G. Forexample, NB-IoT technology may be an example of Low Power Wide AreaNetwork (LPWAN) technology, may be implemented in specifications such asLTE Cat NB1 and/or LTE Cat NB2, and may not be limited to theabove-mentioned names. Additionally and/or alternatively, the radiocommunication technologies implemented in the wireless devices in thepresent disclosure may communicate based on LTE-M technology. Forexample, LTE-M technology may be an example of LPWAN technology and becalled by various names such as enhanced MTC (eMTC). For example, LTE-Mtechnology may be implemented in at least one of the variousspecifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4)LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE Machine TypeCommunication, and/or 7) LTE M, and may not be limited to theabove-mentioned names. Additionally and/or alternatively, the radiocommunication technologies implemented in the wireless devices in thepresent disclosure may include at least one of ZigBee, Bluetooth, and/orLPWAN which take into account low-power communication, and may not belimited to the above-mentioned names. For example, ZigBee technology maygenerate Personal Area Networks (PANs) associated with small/low-powerdigital communication based on various specifications such as IEEE802.15.4 and may be called various names.

FIG. 2 shows an example of wireless devices to which implementations ofthe present disclosure is applied.

Referring to FIG. 2 , a first wireless device 100 and a second wirelessdevice 200 may transmit/receive radio signals to/from an external devicethrough a variety of RATs (e.g., LTE and NR).

In FIG. 2 , {the first wireless device 100 and the second wirelessdevice 200} may correspond to at least one of {the wireless device 100 ato 100 f and the BS 200}, {the wireless device 100 a to 100 f and thewireless device 100 a to 100 f} and/or {the BS 200 and the BS 200} ofFIG. 1 .

The first wireless device 100 may include at least one transceiver, suchas a transceiver 106, at least one processing chip, such as a processingchip 101, and/or one or more antennas 108.

The processing chip 101 may include at least one processor, such aprocessor 102, and at least one memory, such as a memory 104. It isexemplarily shown in FIG. 2 that the memory 104 is included in theprocessing chip 101. Additional and/or alternatively, the memory 104 maybe placed outside of the processing chip 101.

The processor 102 may control the memory 104 and/or the transceiver 106and may be configured to implement the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts describedin the present disclosure. For example, the processor 102 may processinformation within the memory 104 to generate first information/signalsand then transmit radio signals including the first information/signalsthrough the transceiver 106. The processor 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory 104.

The memory 104 may be operably connectable to the processor 102. Thememory 104 may store various types of information and/or instructions.The memory 104 may store a software code 105 which implementsinstructions that, when executed by the processor 102, perform thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure. For example,the software code 105 may implement instructions that, when executed bythe processor 102, perform the descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure. For example, the software code 105 may control theprocessor 102 to perform one or more protocols. For example, thesoftware code 105 may control the processor 102 to perform one or morelayers of the radio interface protocol.

Herein, the processor 102 and the memory 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver 106 may be connected to the processor 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver 106 may include a transmitter and/or a receiver.The transceiver 106 may be interchangeably used with Radio Frequency(RF) unit(s). In the present disclosure, the first wireless device 100may represent a communication modem/circuit/chip.

The second wireless device 200 may include at least one transceiver,such as a transceiver 206, at least one processing chip, such as aprocessing chip 201, and/or one or more antennas 208.

The processing chip 201 may include at least one processor, such aprocessor 202, and at least one memory, such as a memory 204. It isexemplarily shown in FIG. 2 that the memory 204 is included in theprocessing chip 201. Additional and/or alternatively, the memory 204 maybe placed outside of the processing chip 201.

The processor 202 may control the memory 204 and/or the transceiver 206and may be configured to implement the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts describedin the present disclosure. For example, the processor 202 may processinformation within the memory 204 to generate third information/signalsand then transmit radio signals including the third information/signalsthrough the transceiver 206. The processor 202 may receive radio signalsincluding fourth information/signals through the transceiver 106 andthen store information obtained by processing the fourthinformation/signals in the memory 204.

The memory 204 may be operably connectable to the processor 202. Thememory 204 may store various types of information and/or instructions.The memory 204 may store a software code 205 which implementsinstructions that, when executed by the processor 202, perform thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure. For example,the software code 205 may implement instructions that, when executed bythe processor 202, perform the descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure. For example, the software code 205 may control theprocessor 202 to perform one or more protocols. For example, thesoftware code 205 may control the processor 202 to perform one or morelayers of the radio interface protocol.

Herein, the processor 202 and the memory 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver 206 may be connected to the processor 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver 206 may include a transmitter and/or a receiver.The transceiver 206 may be interchangeably used with RF unit. In thepresent disclosure, the second wireless device 200 may represent acommunication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as physical (PHY)layer, Media Access Control (MAC) layer, Radio Link Control (RLC) layer,Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control(RRC) layer, and Service Data Adaptation Protocol (SDAP) layer). The oneor more processors 102 and 202 may generate one or more Protocol DataUnits (PDUs) and/or one or more Service Data Units (SDUs) according tothe descriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure. The one ormore processors 102 and 202 may generate messages, control information,data, or information according to the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts disclosedin the present disclosure. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure and providethe generated signals to the one or more transceivers 106 and 206. Theone or more processors 102 and 202 may receive the signals (e.g.,baseband signals) from the one or more transceivers 106 and 206 andacquire the PDUs, SDUs, messages, control information, data, orinformation according to the descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure may be implemented using firmware or software and thefirmware or software may be configured to include the modules,procedures, or functions. Firmware or software configured to perform thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure may beincluded in the one or more processors 102 and 202 or stored in the oneor more memories 104 and 204 so as to be driven by the one or moreprocessors 102 and 202. The descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure may be implemented using firmware or software in theform of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable ROMs (EEPROMs), flash memories, hard drives, registers,cash memories, computer-readable storage media, and/or combinationsthereof. The one or more memories 104 and 204 may be located at theinterior and/or exterior of the one or more processors 102 and 202. Theone or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 through various technologies such as wired orwireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure, to one ormore other devices. The one or more transceivers 106 and 206 may receiveuser data, control information, and/or radio signals/channels, mentionedin the descriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure, from one ormore other devices. For example, the one or more transceivers 106 and206 may be connected to the one or more processors 102 and 202 andtransmit and receive radio signals. For example, the one or moreprocessors 102 and 202 may perform control so that the one or moretransceivers 106 and 206 may transmit user data, control information, orradio signals to one or more other devices. The one or more processors102 and 202 may perform control so that the one or more transceivers 106and 206 may receive user data, control information, or radio signalsfrom one or more other devices.

The one or more transceivers 106 and 206 may be connected to the one ormore antennas 108 and 208 and the one or more transceivers 106 and 206may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure, through theone or more antennas 108 and 208. In the present disclosure, the one ormore antennas 108 and 208 may be a plurality of physical antennas or aplurality of logical antennas (e.g., antenna ports).

The one or more transceivers 106 and 206 may convert received user data,control information, radio signals/channels, etc., from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc., using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels,etc., processed using the one or more processors 102 and 202 from thebase band signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters. For example, the one or more transceivers 106 and 206 canup-convert OFDM baseband signals to OFDM signals by their (analog)oscillators and/or filters under the control of the one or moreprocessors 102 and 202 and transmit the up-converted OFDM signals at thecarrier frequency. The one or more transceivers 106 and 206 may receiveOFDM signals at a carrier frequency and down-convert the OFDM signalsinto OFDM baseband signals by their (analog) oscillators and/or filtersunder the control of the one or more processors 102 and 202.

In the implementations of the present disclosure, a UE may operate as atransmitting device in UL and as a receiving device in DL. In theimplementations of the present disclosure, a BS may operate as areceiving device in UL and as a transmitting device in DL. Hereinafter,for convenience of description, it is mainly assumed that the firstwireless device 100 acts as the UE, and the second wireless device 200acts as the BS. For example, the processor(s) 102 connected to, mountedon or launched in the first wireless device 100 may be configured toperform the UE behavior according to an implementation of the presentdisclosure or control the transceiver(s) 106 to perform the UE behavioraccording to an implementation of the present disclosure. Theprocessor(s) 202 connected to, mounted on or launched in the secondwireless device 200 may be configured to perform the BS behavioraccording to an implementation of the present disclosure or control thetransceiver(s) 206 to perform the BS behavior according to animplementation of the present disclosure.

In the present disclosure, a BS is also referred to as a Node B (NB), aneNode B (eNB), or a gNB.

FIG. 3 shows an example of a wireless device to which implementations ofthe present disclosure is applied.

The wireless device may be implemented in various forms according to ause-case/service (refer to FIG. 1 ).

Referring to FIG. 3 , wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 2 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit 110 may include a communication circuit 112and transceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 of FIG. 2 and/or the oneor more memories 104 and 204 of FIG. 2 . For example, the transceiver(s)114 may include the one or more transceivers 106 and 206 of FIG. 2and/or the one or more antennas 108 and 208 of FIG. 2 . The control unit120 is electrically connected to the communication unit 110, the memoryunit 130, and the additional components 140 and controls overalloperation of each of the wireless devices 100 and 200. For example, thecontrol unit 120 may control an electric/mechanical operation of each ofthe wireless devices 100 and 200 based onprograms/code/commands/information stored in the memory unit 130. Thecontrol unit 120 may transmit the information stored in the memory unit130 to the exterior (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of the wireless devices 100 and 200. For example, the additionalcomponents 140 may include at least one of a power unit/battery,Input/Output (I/O) unit (e.g., audio I/O port, video I/O port), adriving unit, and a computing unit. The wireless devices 100 and 200 maybe implemented in the form of, without being limited to, the robot (100a of FIG. 1 ), the vehicles (100 b-1 and 100 b-2 of FIG. 1 ), the XRdevice (100 c of FIG. 1 ), the hand-held device (100 d of FIG. 1 ), thehome appliance (100 e of FIG. 1 ), the IoT device (100 f of FIG. 1 ), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a FinTech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 1 ), the BSs (200 of FIG. 1 ), a networknode, etc. The wireless devices 100 and 200 may be used in a mobile orfixed place according to a use-example/service.

In FIG. 3 , the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an Application Processor (AP), an Electronic Control Unit(ECU), a Central Processing Unit (CPU), a Graphical Processing Unit(GPU), and a memory control processor. As another example, the memoryunit 130 may be configured by a RAM, a Dynamic RAM (DRAM), a ROM, aflash memory, a volatile memory, a non-volatile memory, and/or acombination thereof.

FIG. 4 shows an example of UE to which implementations of the presentdisclosure is applied.

Referring to FIG. 4 , a UE 100 may correspond to the first wirelessdevice 100 of FIG. 2 and/or the wireless device 100 or 200 of FIG. 3 .

A UE 100 includes a processor 102, a memory 104, a transceiver 106, oneor more antennas 108, a power management module 110, a battery 112, adisplay 114, a keypad 116, a Subscriber Identification Module (SIM) card118, a speaker 120, and a microphone 122.

The processor 102 may be configured to implement the descriptions,functions, procedures, suggestions, methods and/or operationalflowcharts disclosed in the present disclosure. The processor 102 may beconfigured to control one or more other components of the UE 100 toimplement the descriptions, functions, procedures, suggestions, methodsand/or operational flowcharts disclosed in the present disclosure.Layers of the radio interface protocol may be implemented in theprocessor 102. The processor 102 may include ASIC, other chipset, logiccircuit and/or data processing device. The processor 102 may be anapplication processor. The processor 102 may include at least one ofDSP, CPU, GPU, a modem (modulator and demodulator). An example of theprocessor 102 may be found in SNAPDRAGON™ series of processors made byQualcomm®, EXYNOS™ series of processors made by Samsung®, A series ofprocessors made by Apple®, HELIO™ series of processors made byMediaTek®, ATOM™ series of processors made by Intel® or a correspondingnext generation processor.

The memory 104 is operatively coupled with the processor 102 and storesa variety of information to operate the processor 102. The memory 104may include ROM, RAM, flash memory, memory card, storage medium and/orother storage device. When the embodiments are implemented in software,the techniques described herein can be implemented with modules (e.g.,procedures, functions, etc.) that perform the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts disclosedin the present disclosure. The modules can be stored in the memory 104and executed by the processor 102. The memory 104 can be implementedwithin the processor 102 or external to the processor 102 in which casethose can be communicatively coupled to the processor 102 via variousmeans as is known in the art.

The transceiver 106 is operatively coupled with the processor 102, andtransmits and/or receives a radio signal. The transceiver 106 includes atransmitter and a receiver. The transceiver 106 may include basebandcircuitry to process radio frequency signals. The transceiver 106controls the one or more antennas 108 to transmit and/or receive a radiosignal.

The power management module 110 manages power for the processor 102and/or the transceiver 106. The battery 112 supplies power to the powermanagement module 110.

The display 114 outputs results processed by the processor 102. Thekeypad 116 receives inputs to be used by the processor 102. The keypad116 may be shown on the display 114.

The SIM card 118 is an integrated circuit that is intended to securelystore the International Mobile Subscriber Identity (IMSI) number and itsrelated key, which are used to identify and authenticate subscribers onmobile telephony devices (such as mobile phones and computers). It isalso possible to store contact information on many SIM cards.

The speaker 120 outputs sound-related results processed by the processor102. The microphone 122 receives sound-related inputs to be used by theprocessor 102.

FIGS. 5 and 6 show an example of protocol stacks in a 3GPP basedwireless communication system to which implementations of the presentdisclosure is applied.

In particular, FIG. 5 illustrates an example of a radio interface userplane protocol stack between a UE and a BS and FIG. 6 illustrates anexample of a radio interface control plane protocol stack between a UEand a BS. The control plane refers to a path through which controlmessages used to manage call by a UE and a network are transported. Theuser plane refers to a path through which data generated in anapplication layer, for example, voice data or Internet packet data aretransported. Referring to FIG. 5 , the user plane protocol stack may bedivided into Layer 1 (i.e., a PHY layer) and Layer 2. Referring to FIG.6 , the control plane protocol stack may be divided into Layer 1 (i.e.,a PHY layer), Layer 2, Layer 3 (e.g., an RRC layer), and a Non-AccessStratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as anAccess Stratum (AS).

In the 3GPP LTE system, the Layer 2 is split into the followingsublayers: MAC, RLC, and PDCP. In the 3GPP NR system, the Layer 2 issplit into the following sublayers: MAC, RLC, PDCP and SDAP. The PHYlayer offers to the MAC sublayer transport channels, the MAC sublayeroffers to the RLC sublayer logical channels, the RLC sublayer offers tothe PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAPsublayer radio bearers. The SDAP sublayer offers to 5G core networkQuality of Service (QoS) flows.

In the 3GPP NR system, the main services and functions of the MACsublayer include: mapping between logical channels and transportchannels; multiplexing/de-multiplexing of MAC SDUs belonging to one ordifferent logical channels into/from Transport Blocks (TB) deliveredto/from the physical layer on transport channels; scheduling informationreporting; error correction through Hybrid Automatic Repeat reQuest(HARQ) (one HARQ entity per cell in case of Carrier Aggregation (CA));priority handling between UEs by means of dynamic scheduling; priorityhandling between logical channels of one UE by means of logical channelprioritization; padding. A single MAC entity may support multiplenumerologies, transmission timings and cells. Mapping restrictions inlogical channel prioritization control which numerology(ies), cell(s),and transmission timing(s) a logical channel can use.

Different kinds of data transfer services are offered by MAC. Toaccommodate different kinds of data transfer services, multiple types oflogical channels are defined, i.e., each supporting transfer of aparticular type of information. Each logical channel type is defined bywhat type of information is transferred. Logical channels are classifiedinto two groups: control channels and traffic channels. Control channelsare used for the transfer of control plane information only, and trafficchannels are used for the transfer of user plane information only.Broadcast Control Channel (BCCH) is a downlink logical channel forbroadcasting system control information, Paging Control Channel (PCCH)is a downlink logical channel that transfers paging information, systeminformation change notifications and indications of ongoing PublicWarning Service (PWS) broadcasts, Common Control Channel (CCCH) is alogical channel for transmitting control information between UEs andnetwork and used for UEs having no RRC connection with the network, andDedicated Control Channel (DCCH) is a point-to-point bi-directionallogical channel that transmits dedicated control information between aUE and the network and used by UEs having an RRC connection. DedicatedTraffic Channel (DTCH) is a point-to-point logical channel, dedicated toone UE, for the transfer of user information. A DTCH can exist in bothuplink and downlink. In downlink, the following connections betweenlogical channels and transport channels exist: BCCH can be mapped toBroadcast Channel (BCH); BCCH can be mapped to Downlink Shared Channel(DL-SCH); PCCH can be mapped to Paging Channel (PCH); CCCH can be mappedto DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped toDL-SCH. In uplink, the following connections between logical channelsand transport channels exist: CCCH can be mapped to Uplink SharedChannel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mappedto UL-SCH.

The RLC sublayer supports three transmission modes: Transparent Mode(TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLCconfiguration is per logical channel with no dependency on numerologiesand/or transmission durations. In the 3GPP NR system, the main servicesand functions of the RLC sublayer depend on the transmission mode andinclude: transfer of upper layer PDUs; sequence numbering independent ofthe one in PDCP (UM and AM); error correction through ARQ (AM only);segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs;reassembly of SDU (AM and UM); duplicate detection (AM only); RLC SDUdiscard (AM and UM); RLC re-establishment; protocol error detection (AMonly).

In the 3GPP NR system, the main services and functions of the PDCPsublayer for the user plane include: sequence numbering; headercompression and decompression using Robust Header Compression (ROHC);transfer of user data; reordering and duplicate detection; in-orderdelivery; PDCP PDU routing (in case of split bearers); retransmission ofPDCP SDUs; ciphering, deciphering and integrity protection; PDCP SDUdiscard; PDCP re-establishment and data recovery for RLC AM; PDCP statusreporting for RLC AM; duplication of PDCP PDUs and duplicate discardindication to lower layers. The main services and functions of the PDCPsublayer for the control plane include: sequence numbering; ciphering,deciphering and integrity protection; transfer of control plane data;reordering and duplicate detection; in-order delivery; duplication ofPDCP PDUs and duplicate discard indication to lower layers.

In the 3GPP NR system, the main services and functions of SDAP include:mapping between a QoS flow and a data radio bearer; marking QoS Flow ID(QFI) in both DL and UL packets. A single protocol entity of SDAP isconfigured for each individual PDU session.

In the 3GPP NR system, the main services and functions of the RRCsublayer include: broadcast of system information related to AS and NAS;paging initiated by 5G Core network (5GC) or Next-Generation RadioAccess Network (NG-RAN); establishment, maintenance and release of anRRC connection between the UE and NG-RAN; security functions includingkey management; establishment, configuration, maintenance and release ofSignaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs); mobilityfunctions (including: handover and context transfer, UE cell selectionand reselection and control of cell selection and reselection, inter-RATmobility); QoS management functions; UE measurement reporting andcontrol of the reporting; detection of and recovery from radio linkfailure; NAS message transfer to/from NAS from/to UE.

FIG. 7 shows a frame structure in a 3GPP based wireless communicationsystem to which implementations of the present disclosure is applied.

The frame structure shown in FIG. 7 is purely exemplary and the numberof subframes, the number of slots, and/or the number of symbols in aframe may be variously changed. In the 3GPP based wireless communicationsystem, OFDM numerologies (e.g., SCS, Transmission Time Interval (TTI)duration) may be differently configured between a plurality of cellsaggregated for one UE. For example, if a UE is configured with differentSCSs for cells aggregated for the cell, an (absolute time) duration of atime resource (e.g., a subframe, a slot, or a TTI) including the samenumber of symbols may be different among the aggregated cells. Herein,symbols may include OFDM symbols (or Cyclic Prefix (CP)-OFDM symbols),SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM)symbols).

Referring to FIG. 7 , downlink and uplink transmissions are organizedinto frames. Each frame has T_(f)=10 ms duration. Each frame is dividedinto two half-frames, where each of the half-frames has 5 ms duration.Each half-frame consists of 5 subframes, where the duration T_(sf) persubframe is 1 ms. Each subframe is divided into slots and the number ofslots in a subframe depends on a subcarrier spacing. Each slot includes14 or 12 OFDM symbols based on a CP. In a normal CP, each slot includes14 OFDM symbols and, in an extended CP, each slot includes 12 OFDMsymbols. The numerology is based on exponentially scalable subcarrierspacing Δf=2^(u)*15 kHz.

Table 3 shows the number of OFDM symbols per slot N^(slot) _(symb), thenumber of slots per frame N^(frame,u) _(slot), and the number of slotsper subframe N^(subframe,u) _(slot) for the normal CP, according to thesubcarrier spacing Δf=2^(u)*15 kHz.

TABLE 3 u N^(slot) _(symb) N^(frame, u) _(slot) N^(subframe, u) _(slot)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

Table 4 shows the number of OFDM symbols per slot N^(slot) _(symb), thenumber of slots per frame N^(frame,u) _(slot), and the number of slotsper subframe N^(subframe,u) _(slot) for the extended CP, according tothe subcarrier spacing Δf=2^(u)*15 kHz.

TABLE 4 u N^(slot) _(symb) N^(frame, u) _(slot) N^(subframe, u) _(slot)2 12 40 4

A slot includes plural symbols (e.g., 14 or 12 symbols) in the timedomain. For each numerology (e.g., subcarrier spacing) and carrier, aresource grid of N^(size,u) _(grid,x)*N^(RB) _(sc) subcarriers andN^(subframe,u) _(symb) OFDM symbols is defined, starting at CommonResource Block (CRB) N^(start,u) _(grid,x) indicated by higher-layersignaling (e.g., RRC signaling), where N^(size,u) _(grid,x) is thenumber of Resource Blocks (RBs) in the resource grid and the subscript xis DL for downlink and UL for uplink. N^(RB) _(sc) is the number ofsubcarriers per RB. In the 3GPP based wireless communication system,N^(RB) _(sc) is 12 generally. There is one resource grid for a givenantenna port p, subcarrier spacing configuration u, and transmissiondirection (DL or UL). The carrier bandwidth N^(size,u) _(grid) forsubcarrier spacing configuration u is given by the higher-layerparameter (e.g., RRC parameter). Each element in the resource grid forthe antenna port p and the subcarrier spacing configuration u isreferred to as a Resource Element (RE) and one complex symbol may bemapped to each RE. Each RE in the resource grid is uniquely identifiedby an index k in the frequency domain and an index l representing asymbol location relative to a reference point in the time domain. In the3GPP based wireless communication system, an RB is defined by 12consecutive subcarriers in the frequency domain.

In the 3GPP NR system, RBs are classified into CRBs and PhysicalResource Blocks (PRBs). CRBs are numbered from 0 and upwards in thefrequency domain for subcarrier spacing configuration u. The center ofsubcarrier 0 of CRB 0 for subcarrier spacing configuration u coincideswith ‘point A’ which serves as a common reference point for resourceblock grids. In the 3GPP NR system, PRBs are defined within a BandWidthPart (BWP) and numbered from 0 to N^(size) _(BWP,i)−1, where i is thenumber of the bandwidth part. The relation between the physical resourceblock n_(PRB) in the bandwidth part i and the common resource blockn_(CRB) is as follows: n_(PRB)=n_(CRB)+N^(size) _(BWP,i), where N^(size)_(BWP,i) is the common resource block where bandwidth part startsrelative to CRB 0. The BWP includes a plurality of consecutive RBs. Acarrier may include a maximum of N (e.g., 5) BWPs. A UE may beconfigured with one or more BWPs on a given component carrier. Only oneBWP among BWPs configured to the UE can active at a time. The active BWPdefines the UE's operating bandwidth within the cell's operatingbandwidth.

In the present disclosure, the term “cell” may refer to a geographicarea to which one or more nodes provide a communication system, or referto radio resources. A “cell” as a geographic area may be understood ascoverage within which a node can provide service using a carrier and a“cell” as radio resources (e.g., time-frequency resources) is associatedwith bandwidth which is a frequency range configured by the carrier. The“cell” associated with the radio resources is defined by a combinationof downlink resources and uplink resources, for example, a combinationof a DL Component Carrier (CC) and a UL CC. The cell may be configuredby downlink resources only, or may be configured by downlink resourcesand uplink resources. Since DL coverage, which is a range within whichthe node is capable of transmitting a valid signal, and UL coverage,which is a range within which the node is capable of receiving the validsignal from the UE, depends upon a carrier carrying the signal, thecoverage of the node may be associated with coverage of the “cell” ofradio resources used by the node. Accordingly, the term “cell” may beused to represent service coverage of the node sometimes, radioresources at other times, or a range that signals using the radioresources can reach with valid strength at other times.

In CA, two or more CCs are aggregated. A UE may simultaneously receiveor transmit on one or multiple CCs depending on its capabilities. CA issupported for both contiguous and non-contiguous CCs. When CA isconfigured, the UE only has one RRC connection with the network. At RRCconnection establishment/re-establishment/handover, one serving cellprovides the NAS mobility information, and at RRC connectionre-establishment/handover, one serving cell provides the security input.This cell is referred to as the Primary Cell (PCell). The PCell is acell, operating on the primary frequency, in which the UE eitherperforms the initial connection establishment procedure or initiates theconnection re-establishment procedure. Depending on UE capabilities,Secondary Cells (SCells) can be configured to form together with thePCell a set of serving cells. An SCell is a cell providing additionalradio resources on top of Special Cell (SpCell). The configured set ofserving cells for a UE therefore always consists of one PCell and one ormore SCells. For Dual Connectivity (DC) operation, the term SpCellrefers to the PCell of the Master Cell Group (MCG) or the Primary SCell(PSCell) of the Secondary Cell Group (SCG). An SpCell supports PhysicalUplink Control Channel (PUCCH) transmission and contention-based randomaccess, and is always activated. The MCG is a group of serving cellsassociated with a master node, comprised of the SpCell (PCell) andoptionally one or more SCells. The SCG is the subset of serving cellsassociated with a secondary node, comprised of the PSCell and zero ormore SCells, for a UE configured with DC. For a UE in RRC_CONNECTED notconfigured with CA/DC, there is only one serving cell comprised of thePCell. For a UE in RRC_CONNECTED configured with CA/DC, the term“serving cells” is used to denote the set of cells comprised of theSpCell(s) and all SCells. In DC, two MAC entities are configured in aUE: one for the MCG and one for the SCG.

FIG. 8 shows a data flow example in the 3GPP NR system to whichimplementations of the present disclosure is applied.

Referring to FIG. 8 , “RB” denotes a radio bearer, and “H” denotes aheader. Radio bearers are categorized into two groups: DRBs for userplane data and SRBs for control plane data. The MAC PDU istransmitted/received using radio resources through the PHY layer to/froman external device. The MAC PDU arrives to the PHY layer in the form ofa transport block.

In the PHY layer, the uplink transport channels UL-SCH and Random AccessChannel (RACH) are mapped to their physical channels Physical UplinkShared Channel (PUSCH) and Physical Random Access Channel (PRACH),respectively, and the downlink transport channels DL-SCH, BCH and PCHare mapped to Physical Downlink Shared Channel (PDSCH), PhysicalBroadcast Channel (PBCH) and PDSCH, respectively. In the PHY layer,Uplink Control Information (UCI) is mapped to PUCCH, and DownlinkControl Information (DCI) is mapped to Physical Downlink Control Channel(PDCCH). A MAC PDU related to UL-SCH is transmitted by a UE via a PUSCHbased on an UL grant, and a MAC PDU related to DL-SCH is transmitted bya BS via a PDSCH based on a DL assignment.

Discontinuous Reception (DRX) is described.

The MAC entity may be configured by RRC with a DRX functionality thatcontrols the UE's PDCCH monitoring activity for the MAC entity's C-RNTI,CI-RNTI, CS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI,TPC-PUSCH-RNTI, and TPC-SRS-RNTI. When using DRX operation, the MACentity shall also monitor PDCCH. When in RRC_CONNECTED, if DRX isconfigured, for all the activated Serving Cells, the MAC entity maymonitor the PDCCH discontinuously using the DRX operation.

RRC controls DRX operation by configuring the following parameters:

-   -   drx-onDurationTimer: the duration at the beginning of a DRX        Cycle;    -   drx-SlotOffset: the delay before starting the        drx-onDurationTimer;    -   drx-InactivityTimer: the duration after the PDCCH occasion in        which a PDCCH indicates a new UL or DL transmission for the MAC        entity;    -   drx-RetransmissionTimerDL (per DL HARQ process except for the        broadcast process): the maximum duration until a DL        retransmission is received;    -   drx-RetransmissionTimerUL (per UL HARQ process): the maximum        duration until a grant for UL retransmission is received;    -   drx-LongCycleStartOffset: the Long DRX cycle and drx-StartOffset        which defines the subframe where the Long and Short DRX Cycle        starts;    -   drx-ShortCycle (optional): the Short DRX cycle;    -   drx-ShortCycleTimer (optional): the duration the UE shall follow        the Short DRX cycle;    -   drx-HARQ-RTT-TimerDL (per DL HARQ process except for the        broadcast process): the minimum duration before a DL assignment        for HARQ retransmission is expected by the MAC entity;    -   drx-HARQ-RTT-TimerUL (per UL HARQ process): the minimum duration        before a UL HARQ retransmission grant is expected by the MAC        entity;    -   ps-Wakeup (optional): the configuration to start associated        drx-onDurationTimer in case DCP is monitored but not detected;    -   ps-Periodic_CSI_Transmit (optional): the configuration to report        periodic CSI during the time duration indicated by        drx-onDuration Timer in case DCP is configured but associated        drx-onDuration Timer is not started;    -   ps-TransmitPeriodicL1-RSRP (optional): the configuration to        transmit periodic L1-RSRP report(s) during the time duration        indicated by drx-onDuration Timer in case DCP is configured but        associated drx-onDuration Timer is not started.

When a DRX cycle is configured, the Active Time includes the time while:

-   -   drx-onDurationTimer or drx-InactivityTimer or        drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or        ra-ContentionResolution Timer is running; or    -   a Scheduling Request is sent on PUCCH and is pending; or    -   a PDCCH indicating a new transmission addressed to the C-RNTI of        the MAC entity has not been received after successful reception        of a Random Access Response for the Random Access Preamble not        selected by the MAC entity among the contention-based Random        Access Preamble.

When DRX is configured, the MAC entity shall:

-   -   1> if a MAC PDU is received in a configured downlink assignment:    -   2> start the drx-HARQ-RTT-TimerDL for the corresponding HARQ        process in the first symbol after the end of the corresponding        transmission carrying the DL HARQ feedback;    -   2> stop the drx-RetransmissionTimerDL for the corresponding HARQ        process.    -   1> if a MAC PDU is transmitted in a configured uplink grant:    -   2> start the drx-HARQ-RTT-TimerUL for the corresponding HARQ        process in the first symbol after the end of the first        repetition of the corresponding PUSCH transmission;    -   2> stop the drx-RetransmissionTimerUL for the corresponding HARQ        process.    -   1> if a drx-HARQ-RTT-TimerDL expires:    -   2> if the data of the corresponding HARQ process was not        successfully decoded:    -   3> start the drx-RetransmissionTimerDL for the corresponding        HARQ process in the first symbol after the expiry of        drx-HARQ-RTT-TimerDL.    -   1> if a drx-HARQ-RTT-TimerUL expires:    -   2> start the drx-RetransmissionTimerUL for the corresponding        HARQ process in the first symbol after the expiry of        drx-HARQ-RTT-TimerUL.    -   1> if a DRX Command MAC CE or a Long DRX Command MAC CE is        received:    -   2> stop drx-onDurationTimer;    -   2> stop drx-InactivityTimer.    -   1> if drx-InactivityTimer expires or a DRX Command MAC CE is        received:    -   2> if the Short DRX cycle is configured:    -   3> start or restart drx-ShortCycleTimer in the first symbol        after the expiry of drx-InactivityTimer or in the first symbol        after the end of DRX Command MAC CE reception;    -   3> use the Short DRX Cycle.    -   2> else:    -   3> use the Long DRX cycle.    -   1> if drx-ShortCycleTimer expires:    -   2> use the Long DRX cycle.    -   1> if a Long DRX Command MAC CE is received:    -   2> stop drx-ShortCycleTimer;    -   2> use the Long DRX cycle.    -   1> if the Short DRX Cycle is used, and [(SFN×10)+subframe        number] modulo (drx-ShortCycle)=(drx-StartOffset) modulo        (drx-ShortCycle):    -   2> start drx-onDuration Timer after drx-SlotOffset from the        beginning of the subframe.    -   1> if the Long DRX Cycle is used, and [(SFN×10)+subframe number]        modulo (drx-LongCycle)=drx-StartOffset:    -   2> if DCP is configured for the active DL BWP:    -   3> if DCP indication associated with the current DRX Cycle        received from lower layer indicated to start        drx-onDurationTimer; or    -   3> if all DCP occasion(s) in time domain associated with the        current DRX Cycle occurred in Active Time considering        grants/assignments/DRX Command MAC CE/Long DRX Command MAC CE        received and Scheduling Request sent until 4 ms prior to start        of the last DCP occasion, or within BWP switching interruption        length, or during a measurement gap; or    -   3> if ps-Wakeup is configured with value true and DCP indication        associated with the current DRX Cycle has not been received from        lower layers:    -   4> start drx-onDuration Timer after drx-SlotOffset from the        beginning of the subframe.    -   2> else:    -   3> start drx-onDuration Timer after drx-SlotOffset from the        beginning of the subframe.

Note: In case of unaligned SFN across carriers in a cell group, the SFNof the SpCell is used to calculate the DRX duration.

-   -   1> if the MAC entity is in Active Time:    -   2> monitor the PDCCH;    -   2> if the PDCCH indicates a DL transmission:    -   3> start the drx-HARQ-RTT-TimerDL for the corresponding HARQ        process in the first symbol after the end of the corresponding        transmission carrying the DL HARQ feedback, regardless of LBT        failure indication from lower layers;    -   Note: When HARQ feedback is postponed by PDSCH-to-HARQ_feedback        timing indicating a non-numerical kl value, the corresponding        transmission opportunity to send the DL HARQ feedback is        indicated in a later PDCCH requesting the HARQ-ACK feedback.    -   3> stop the drx-RetransmissionTimerDL for the corresponding HARQ        process.    -   3> if the PDSCH-to-HARQ_feedback timing indicate a non-numerical        kl value:    -   4> start the drx-RetransmissionTimerDL in the first symbol after        the PDSCH transmission for the corresponding HARQ process.    -   2> if the PDCCH indicates a UL transmission:    -   3> start the drx-HARQ-RTT-TimerUL for the corresponding HARQ        process in the first symbol after the end of the first        repetition of the corresponding PUSCH transmission, regardless        of LBT failure indication from lower layers;    -   3> stop the drx-RetransmissionTimerUL for the corresponding HARQ        process.    -   2> if the PDCCH indicates a new transmission (DL or UL):    -   3> start or restart drx-InactivityTimer in the first symbol        after the end of the PDCCH reception.    -   1> if DCP is configured for the active DL BWP; and    -   1> if the current symbol n occurs within drx-onDuration Timer        duration; and    -   1> if drx-onDurationTimer associated with the current DRX cycle        is not started; and    -   1> if the MAC entity would not be in Active Time considering        grants/assignments/DRX Command MAC CE/Long DRX Command MAC CE        received and Scheduling Request sent until 4 ms prior to symbol        n when evaluating all DRX Active Time conditions:    -   2> not transmit periodic SRS and semi-persistent SRS;    -   2> not report semi-persistent CSI configured on PUSCH;    -   2> if ps-Periodic_CSI_Transmit is not configured with value        true:    -   3> if ps-TransmitPeriodicL1-RSRP is not configured with value        true:    -   4> not report periodic CSI on PUCCH.    -   3> else:    -   4> not report periodic CSI on PUCCH, except L1-RSRP report(s).    -   1> else:    -   2> in current symbol n, if the MAC entity would not be in Active        Time considering grants/assignments/DRX Command MAC CE/Long DRX        Command MAC CE received and Scheduling Request sent until 4 ms        prior to symbol n when evaluating all DRX Active Time        conditions:    -   3> not transmit periodic SRS and semi-persistent SRS;    -   3> not report CSI on PUCCH and semi-persistent CSI configured on        PUSCH.    -   2> if CSI masking (csi-Mask) is setup by upper layers:    -   3> in current symbol n, if drx-onDuration Timer would not be        running considering grants/assignments/DRX Command MAC CE/Long        DRX Command MAC CE received until 4 ms prior to symbol n when        evaluating all DRX Active Time conditions:    -   4> not report CSI on PUCCH.

Regardless of whether the MAC entity is monitoring PDCCH or not, the MACentity transmits HARQ feedback, aperiodic CSI on PUSCH, and aperiodicSRS when such is expected.

The MAC entity needs not to monitor the PDCCH if it is not a completePDCCH occasion (e.g. the Active Time starts or ends in the middle of aPDCCH occasion).

Sidelink (SL) transmission and/or communication in 5G NR is described.Section 5.7 and Section 16.9 of 3GPP TS 38.300 V16.1.0 can be referred.

FIG. 9 shows an example of NG-RAN architecture supporting PC5 interfaceto which implementations of the present disclosure is applied.

Referring to FIG. 9 , sidelink transmission and reception over the PC5interface are supported when the UE is inside NG-RAN coverage,irrespective of which RRC state the UE is in, and when the UE is outsideNG-RAN coverage.

Support of V2X services via the PC5 interface can be provided by NRsidelink communication and/or V2X sidelink communication. NR sidelinkcommunication may be used to support other services than V2X services.

NR sidelink communication can support one of three types of transmissionmodes for a pair of a Source Layer-2 ID and a Destination Layer-2 ID inthe AS:

-   -   (1) Unicast transmission, characterized by:        -   Support of one PC5-RRC connection between peer UEs for the            pair;        -   Transmission and reception of control information and user            traffic between peer UEs in sidelink;        -   Support of sidelink HARQ feedback;        -   Support of RLC AM;        -   Detection of radio link failure for the PC5-RRC connection.    -   (2) Groupcast transmission, characterized by:        -   Transmission and reception of user traffic among UEs            belonging to a group in sidelink;        -   Support of sidelink HARQ feedback.    -   (3) Broadcast transmission, characterized by:        -   Transmission and reception of user traffic among UEs in            sidelink.

Two sidelink resource allocation modes are supported, i.e., mode 1 andmode 2. In mode 1, the sidelink resource allocation is provided by thenetwork. In mode 2, UE decides the SL transmission resources and timingin the resource pool.

Mode 1, which may be called scheduled resource allocation, may becharacterized by the following:

-   -   The UE needs to be RRC_CONNECTED in order to transmit data;    -   NG-RAN schedules transmission resources.

Mode 2, which may be called UE autonomous resource selection, may becharacterized by the following:

-   -   The UE can transmit data when inside NG-RAN coverage,        irrespective of which RRC state the UE is in, and when outside        NG-RAN coverage;    -   The UE autonomously selects transmission resources from a pool        of resources.

For NR sidelink communication, the UE performs sidelink transmissionsonly on a single carrier.

In mode 1, NG-RAN can dynamically allocate resources to the UE via theSidelink Radio Network Temporary Identifier (SL-RNTI) on PDCCH(s) for NRsidelink communication.

In addition, NG-RAN can allocate sidelink resources to UE with two typesof configured sidelink grants:

-   -   With type 1, RRC directly provides the configured sidelink grant        only for NR sidelink communication;    -   With type 2, RRC defines the periodicity of the configured        sidelink grant while PDCCH can either signal and activate the        configured sidelink grant, or deactivate it. The PDCCH is        addressed to SL Configured Scheduling RNTI (SL-CS-RNTI) for NR        sidelink communication and SL semi-persistent scheduling V2X        RNTI (V-RNTI) for V2X sidelink communication.

For the UE performing NR sidelink communication, there can be more thanone configured sidelink grant activated at a time on the carrierconfigured for sidelink transmission

When beam failure or physical layer problem occurs on NR Uu, the UE cancontinue using the configured sidelink grant type 1. During handover,the UE can be provided with configured sidelink grants via handovercommand, regardless of the type. If provided, the UE activates theconfigured sidelink grant type 1 upon reception of the handover command.

The UE can send Sidelink Buffer Status Report (SL BSR) to supportscheduler operation in NG-RAN. The sidelink buffer status reports referto the data that is buffered in for a group of Logical Channels (LCG)per destination in the UE. Eight LCGs are used for reporting of thesidelink buffer status reports. Two formats, which are SL BSR andtruncated SL BSR, are used.

In mode 2, the UE autonomously selects sidelink grant from a pool ofresources provided by broadcast system information or dedicatedsignalling while inside NG-RAN coverage or by pre-configuration whileoutside NG-RAN coverage.

For NR sidelink communication, the pools of resources can be providedfor a given validity area where the UE does not need to acquire a newpool of resources while moving within the validity area, at least whenthis pool is provided by System Information Block (SIB) (e.g., reusevalid area of NR SIB). NR SIB validity mechanism is reused to enablevalidity area for SL resource pool configured via broadcasted systeminformation.

The UE is allowed to temporarily use UE autonomous resource selectionwith random selection for sidelink transmission based on configurationof the exceptional transmission resource pool.

When a UE is inside NG-RAN coverage, NR sidelink communication and/orV2X sidelink communication can be configured and controlled by NG-RANvia dedicated signalling or system information:

-   -   The UE should support and be authorized to perform NR sidelink        communication and/or V2X sidelink communication in NG-RAN;    -   If configured, the UE performs V2X sidelink communication unless        otherwise specified;    -   NG-RAN can provide the UE with intra-carrier sidelink        configuration, inter-carrier sidelink configuration and anchor        carrier which provides sidelink configuration via a Uu carrier        for NR sidelink communication and/or V2X Sidelink communication;    -   When the UE cannot simultaneously perform both NR sidelink        transmission and NR uplink transmission in time domain,        prioritization between both transmissions is done based on their        priorities and thresholds configured by the NG-RAN.

When a UE is outside NG-RAN coverage, Sidelink Radio Bearer (SLRB)configuration are preconfigured to the UE for NR sidelink communication.

The UE in RRC_CONNECTED performs NR sidelink communication and/or V2Xsidelink communication. The UE sends Sidelink UE Information to NG-RANin order to request or release sidelink resources and report QoSinformation for each destination.

NG-RAN provides RRCReconfiguration to the UE in order to provide the UEwith dedicated sidelink configuration. The RRCReconfiguration mayinclude SLRB configuration for NR sidelink communication as well aseither sidelink scheduling configuration or resource pool configuration.If UE has received SLRB configuration via system information, UE shouldcontinue using the configuration to perform sidelink data transmissionsand receptions until a new configuration is received via theRRCReconfiguration.

NG-RAN may also configure measurement and reporting of Channel BusyRatio (CBR) and reporting of location information to the UE viaRRCReconfiguration.

During handover, the UE performs sidelink transmission and receptionbased on configuration of the exceptional transmission resource pool orconfigured sidelink grant type 1 and reception resource pool of thetarget cell as provided in the handover command.

The UE in RRC_IDLE or RRC_INACTIVE performs NR sidelink communicationand/or V2X sidelink communication. NG-RAN may provide common sidelinkconfiguration to the UE in RRC_IDLE or RRC_INACTIVE via systeminformation for NR sidelink communication and/or V2X sidelinkcommunication. UE receives resource pool configuration and SLRBconfiguration via SIB12 for NR sidelink communication, and/or resourcepool configuration via SIB13 and SIB14 for V2X sidelink communication.If UE has received SLRB configuration via dedicated signalling, UEshould continue using the configuration to perform sidelink datatransmissions and receptions until a new configuration is received viasystem information.

When the UE performs cell reselection, the UE interested in V2Xservice(s) considers at least whether NR sidelink communication and/orV2X sidelink communication are supported by the cell. The UE mayconsider the following carrier frequency as the highest priorityfrequency, except for the carrier only providing the anchor carrier:

-   -   the frequency providing both NR sidelink communication and V2X        sidelink communication, if configured to perform both NR        sidelink communication and V2X sidelink communication;    -   the frequency providing NR sidelink communication, if configured        to perform only NR sidelink communication.

Radio protocol architecture for NR sidelink communication may be asfollows.

-   -   The AS protocol stack for the control plane in the PC5 interface        consists of RRC, PDCP, RLC and MAC sublayers, and the physical        layer.    -   For support of PC5-S protocol, PC5-S is located on top of PDCP,        RLC and MAC sublayers, and the physical layer for the control        plane in the PC5 interface.    -   The AS protocol stack for SBCCH in the PC5 interface consists of        RRC, RLC, MAC sublayers, and the physical layer.    -   The AS protocol stack for user plane in the PC5 interface        consists of SDAP, PDCP, RLC and MAC sublayers, and the physical        layer.

SLRB are categorized into two groups: Sidelink Data Radio Bearers (SLDRB) for user plane data and Sidelink Signalling Radio Bearers (SL SRB)for control plane data. Separate SL SRBs using different SCCHs areconfigured for PC5-RRC and PC5-S signaling respectively.

Physical Sidelink Control Channel (PSCCH) indicates resource and othertransmission parameters used by a UE for PSSCH. PSCCH transmission isassociated with a De-Modulation Reference Signal (DM-RS).

Physical Sidelink Shared Channel (PSSCH) transmits the TBs of datathemselves, and control information for HARQ procedures and ChannelState Information (CSI) feedback triggers, etc. At least 5 OFDM symbolswithin a slot are used for PSSCH transmission. PSSCH transmission isassociated with a DM-RS and may be associated with a Phase TrackingReference Signal (PT-RS).

Physical Sidelink Feedback Channel (PSFCH) carries HARQ feedback overthe sidelink from a UE which is an intended recipient of a PSSCHtransmission to the UE which performed the transmission. PSFCH sequenceis transmitted in one PRB repeated over two OFDM symbols near the end ofthe sidelink resource in a slot.

The sidelink synchronization signal consists of Sidelink Primary andSidelink Secondary Synchronization Signals (S-PSS, S-SSS), eachoccupying 2 symbols and 127 subcarriers. Physical Sidelink BroadcastChannel (PSBCH) occupies 7 and 5 symbols for normal and extended cyclicprefix cases respectively, including the associated DM-RS.

Sidelink HARQ feedback uses PSFCH and can be operated in one of twooptions. In one option, PSFCH transmits either Acknowledgement (ACK) orNegative ACK (NACK) using a resource dedicated to a single PSFCHtransmitting UE. In another option, PSFCH transmits NACK, or no PSFCHsignal is transmitted, on a resource that can be shared by multiplePSFCH transmitting UEs.

In sidelink resource allocation mode 1, a UE which received PSFCH canreport sidelink HARQ feedback to gNB via PUCCH or PUSCH.

For unicast, CSI Reference Signal (CSI-RS) is supported for CSImeasurement and reporting in sidelink. A CSI report is carried in a MACControl Element (CE).

The MAC sublayer provides the following services and functions over thePC5 interface in addition to the services and functions described aboveby referring to FIGS. 5 and 6 .

-   -   Radio resource selection;    -   Packet filtering;    -   Priority handling between uplink and sidelink transmissions for        a given UE;    -   Sidelink CSI reporting.

With Logical Channel Prioritization (LCP) restrictions in MAC, onlysidelink logical channels belonging to the same destination can bemultiplexed into a MAC PDU for every unicast, groupcast and broadcasttransmission which is associated to the destination. NG-RAN can alsocontrol whether a sidelink logical channel can utilize the resourcesallocated to a configured sidelink grant type 1.

For packet filtering, a SL-SCH MAC header including portions of bothSource Layer-2 ID and a Destination Layer-2 ID is added to each MAC PDU.Logical channel ID (LCID) included within a MAC subheader uniquelyidentifies a logical channel within the scope of the Source Layer-2 IDand Destination Layer-2 ID combination.

The following logical channels are used in sidelink:

-   -   Sidelink Control Channel (SCCH): a sidelink channel for        transmitting control information from one UE to other UE(s);    -   Sidelink Traffic Channel (STCH): a sidelink channel for        transmitting user information from one UE to other UE(s);    -   Sidelink Broadcast Control Channel (SBCCH): a sidelink channel        for broadcasting sidelink system information from one UE to        other UE(s).

The following connections between logical channels and transportchannels exist:

-   -   SCCH can be mapped to Sidelink Shared Channel (SL-SCH);    -   STCH can be mapped to SL-SCH;    -   SBCCH can be mapped to Sidelink Broadcast Channel (SL-BCH).

The RRC sublayer provides the following services and functions over thePC5 interface:

-   -   Transfer of a PC5-RRC message between peer UEs;    -   Maintenance and release of a PC5-RRC connection between two UEs;    -   Detection of sidelink radio link failure for a PC5-RRC        connection.

A PC5-RRC connection is a logical connection between two UEs for a pairof Source and Destination Layer-2 IDs which is considered to beestablished after a corresponding PC5 unicast link is established. Thereis one-to-one correspondence between the PC5-RRC connection and the PC5unicast link. A UE may have multiple PC5-RRC connections with one ormore UEs for different pairs of Source and Destination Layer-2 IDs.

Separate PC5-RRC procedures and messages are used for a UE to transferUE capability and sidelink configuration including SLRB configuration tothe peer UE. Both peer UEs can exchange their own UE capability andsidelink configuration using separate bi-directional procedures in bothsidelink directions.

If it is not interested in sidelink transmission, if sidelink Radio LinkFailure (RLF) on the PC5-RRC connection is declared, or if the Layer-2link release procedure is completed or if the T400 is expired, UEreleases the PC5-RRC connection.

Sidelink resource allocation is described in detail. If the transmittingUE (e.g., TX UE) is in RRC_CONNECTED and configured for gNB scheduledsidelink resource allocation (e.g., mode 1), the TX UE may transmitsidelink UE information including traffic pattern of Service, TXcarriers and/or RX carriers mapped to service, QoS information relatedto service (e.g., 5G QoS Identifier (5QI), ProSe-Per-Packet Priority(PPPP), ProSe-Per-Packet reliability (PPPR), QoS Class Identifier (QCI)value), and destination related to service.

After receiving the sidelink UE information, the gNB constructs sidelinkconfiguration at least including one or more resource pools for serviceand sidelink BSR configuration. The gNB signals the sidelinkconfiguration to the TX UE and then the TX UE configures lower layerswith sidelink configuration.

If a message becomes available in L2 buffer for sidelink transmission,the TX UE triggers Scheduling Request (SR), so that the TX UE transmitsPUCCH resource. If PUCCH resource is not configured, the TX UE performsrandom access procedure as the SR. If an uplink grant is given at aresult of the SR, the TX UE transmits sidelink BSR to the gNB. Thesidelink BSR indicates at least a destination index, a LCG, and a buffersize corresponding to the destination.

After receiving the sidelink BSR, the gNB transmits a sidelink grant tothe TX UE, e.g., by sending DCI in PDCCH. The DCI may include anallocated sidelink resource. If the TX UE receives the DCI, the TX UEuses the sidelink grant for transmission to the receiving UE (e.g., RXUE).

Alternatively, if the TX UE is configured for UE autonomous schedulingof sidelink resource allocation (e.g., mode 2) regardless of RRC state,the TX UE autonomously select or reselect sidelink resources to create asidelink grant used for transmission to the RX UE.

When UE performs sidelink reception, UE should monitor all slotsconfigured for sidelink transmission because UE does not know when otherUE will perform sidelink transmission in which UE is interested. Thus,UE may unnecessarily consume its power to monitor all slots.

Meanwhile, it is discussed to support SL DRX for sidelink in 5G NRRel-17. In this case, since the base station configures DL DRX, it maybe preferable that the base station configures DL DRX with reference toSL DRX. However, the base station has a problem in that it is difficultto understand SL transmission not controlled by the base station, and itis difficult to align the DL DRX and SL DRX because the base stationdoes not know the SL resource selected or reselected by UE.

According to implementations of the present disclosure, UE may receiveSL DRX information from the other UE.

According to implementations of the present disclosure, UE may informthe network about the received SL DRX information. The SL DRXinformation may be constructed for each pair of source/destination.

According to implementations of the present disclosure, UE mayprioritize one SL/DL reception while skipping the other SL reception. Ifthe network and/or the first other UE (e.g., relay UE) provides thefirst SL DRX configuration and the second other UE provides the secondSL DRX configuration for the same destination, same pair ofsource/destination and/or same PC5-RRC connection, UE may monitor timedurations (i.e., SL active time) according to both SL DRXconfigurations. If UE deprioritizes sidelink reception due to e.g.,prioritized downlink reception, prioritized sidelink transmission,prioritized sidelink reception from the third other UE, or prioritizeduplink transmission, UE may skip monitoring the PSCCH transmissioncorresponding to the deprioritized sidelink reception.

According to implementations of the present disclosure, UE may informthe network and/or the other UE about updated SL DRX informationincluding the PSCCH duration for the skipped transmission.

The following drawings are created to explain specific embodiments ofthe present disclosure. The names of the specific devices or the namesof the specific signals/messages/fields shown in the drawings areprovided by way of example, and thus the technical features of thepresent disclosure are not limited to the specific names used in thefollowing drawings.

FIG. 10 shows an example of a method performed by a third wirelessdevice to which implementation of the present disclosure is applied.

In step S1000, the method includes establishing at least one firstPC5-RRC connection with a first wireless device for a first pair ofsource and destination.

In step S1010, the method includes establishing at least one secondPC5-RRC connection with a second wireless device for a second pair ofsource and destination.

In step S1020, the method includes receiving, from the first wirelessdevice, first SL DRX information.

In step S1030, the method includes receiving, from the second wirelessdevice, second SL DRX information.

In some implementations, the third wireless device may be configuredwith one or more pools of resources. The method may include receivingthe first and second SL DRX information on one of the pools of resourcesfor sidelink reception. The first and second SL DRX information may bereceived via 1st stage SCI on PSCCH, 2nd stage SCI on PSSCH or a MAC CEon PSSCH. The first and second SL DRX information may include PSCCHduration(s) for one or more next transmissions from the first and/orsecond wireless device performing periodic transmissions. The SL DRXinformation may include the priority of the corresponding PSSCHtransmission and/or whether the corresponding PSSCH transmission isprioritized or not. The corresponding PSSCH transmission may be eitherthe PSSCH transmission scheduled by the PSCCH or a next PSSCHtransmission reserved by the PSCCH.

In step S1040, the method includes informing a network about the firstand second SL DRX information. Each of the first and second SL DRXinformation is constructed for each pair of source and destination.

In some implementations, the first and second SL DRX information may beinformed to the network via a single message. For example, the first andsecond SL DRX information may be informed to the network via a RRCmessage or UCI or MAC CE.

In some implementations, the first and second SL DRX information may beconstructed for each destination, each pair of source/destination and/oreach PC5-RRC connection.

In some implementations, the method may include receiving DL DRXconfiguration from the network. The method may include receiving SL DRXconfiguration from the network and/or first/second wireless device. Bothconfigurations may not be overlapped in time. The SL DRX configurationmay be provided for each destination, each pair of source/destinationand/or each PC5-RRC connection. Thus, the method may include receiving alist of SL DRX configurations. Each SL DRX configuration may be appliedto the corresponding destination, corresponding pair ofsource/destination and/or corresponding PC5-RRC connection.

In some implementations, the method may include monitoring PDCCHaccording to the DL DRX configuration, while monitoring SCIs on PSCCHaccording to the SL DRX configuration. If the SL DRX configuration hasbeen not provided or not included in the list for the correspondingdestination, corresponding pair of source/destination and/orcorresponding PC5-RRC connection, the method may include constructingits own SL DRX configuration.

In some implementations, a first SL DRX configuration may be receivedfrom the network and/or the first wireless device, a second SL DRXconfiguration may be received from the second wireless device. The firstSL DRX configuration and the second SL DRX configuration may beconfigured for same destination, same pair of source/destination and/orsame PC5-RRC connection. In this case, the method may include monitoringtime durations (i.e., SL active time) according to both the first andsecond SL DRX configurations. For example, if the network and/or thefirst other wireless device (e.g., relay UE) provides the first SL DRXconfiguration and the second other wireless device provides the secondSL DRX configuration for the same destination, same pair ofsource/destination and/or same PC5-RRC connection, the method mayinclude monitoring time durations (i.e., SL active time) according toboth SL DRX configurations.

For example, a first set of time durations may be determined based onthe first SL DRX configuration. A second set of time durations may bedetermined based on the second SL DRX configuration. Each time durationmay include at least one PSCCH duration. Only time durations overlappedby both the first set of time durations and the second set of timedurations may be monitored. Or, i) time durations overlapped by both thefirst set of time durations and the second set of time durations, andii) either one of the first set of time durations and the second set oftime durations may be monitored. Or, both the first set of timedurations and the second set of time durations may be monitored.

For example, the method may include determining the first set of timedurations according to the first SL DRX configuration and the second setof time durations according to the second SL DRX configuration. Themethod may include only monitoring time durations overlapped by both thefirst and second sets of time durations. Or, the method may includemonitoring the first set of time durations and the overlapped timedurations. Or, the method may include monitoring the second set of timedurations and the overlapped time durations. Or, the method may includemonitoring both the first set and the second set of time durations. Thetime duration may be at least PSCCH duration.

In some implementations, the method may include considering the PSCCHduration(s) as a SL active time for sidelink reception from thefirst/second wireless device. If one of the PSCCH durations determinedis overlapped with one of PDCCH durations determined by the DL DRXconfiguration, the overlapped PSCCH duration may not be included in theSL active time. Thus, PSCCH may not be needed to be monitored in theoverlapped PSCCH duration.

In some implementations, the method may include monitoring PSCCHtransmission(s) in the active time to receive sidelink transmission fromthe first/second wireless device.

In some implementations, based on deprioritizing sidelink reception,monitoring PSCCH transmission corresponding to the deprioritizedsidelink reception may be skipped. For example, if the network providesDL DRX configuration and the first/second wireless device provides SLDRX configuration, and if sidelink reception is deprioritized due to,e.g., downlink reception, sidelink transmission or uplink transmission,the method may include skipping monitoring the PSCCH transmissioncorresponding to the deprioritized sidelink reception.

In some implementations, based on a PSCCH transmission indicating ahigher priority value than a priority value of an overlappedtransmission/reception and/or the PSCCH transmission indicating that acorresponding PSSCH transmission is deprioritized or not prioritized,monitoring the corresponding PSSCH transmission may be skipped. That is,if the PSCCH transmission indicates a higher priority value than thepriority value of an overlapped transmission/reception, and/or if thePSCCH transmission indicates that the corresponding PSSCH transmissionis deprioritized or not prioritized, the method may include skippingmonitoring the corresponding PSSCH transmission. The overlappedtransmission/reception may include at least one of a sidelinktransmission, a sidelink reception, a downlink reception and/or anuplink transmission.

In some implementations, information on a duration for the skippedcorresponding PSSCH duration may be informed to a network and/or thefirst wireless device and/or the second wireless device. That is, themethod may include informing the network and/or the first/secondwireless device about the PSCCH duration for the skipped transmission.

In some implementations, the third wireless device may be incommunication with at least one of a mobile device, a network, and/orautonomous vehicles other than the third wireless device.

Furthermore, the method in perspective of the third wireless devicedescribed above in FIG. 10 may be performed by the first wireless device100 shown in FIG. 2 , the wireless device 100 shown in FIG. 3 , and/orthe UE 100 shown in FIG. 4 .

More specifically, the third wireless device comprises at least onetransceiver, at least one processor, and at least one memory operablyconnectable to the at least one processor and storing instructions that,based on being executed by the at least one processor, performoperations below.

The third wireless device establishes at least one first PC5-RRCconnection with a first wireless device for a first pair of source anddestination.

The third wireless device establishes at least one second PC5-RRCconnection with a second wireless device for a second pair of source anddestination.

The third wireless device receives, from the first wireless device viathe at least one transceiver, first SL DRX information.

The third wireless device receives, from the second wireless device viathe at least one transceiver, second SL DRX information.

In some implementations, the third wireless device may be configuredwith one or more pools of resources. The third wireless device mayreceive the first and second SL DRX information on one of the pools ofresources for sidelink reception. The first and second SL DRXinformation may be received via 1st stage SCI on PSCCH, 2nd stage SCI onPSSCH or a MAC CE on PSSCH. The first and second SL DRX information mayinclude PSCCH duration(s) for one or more next transmissions from thefirst and/or second wireless device performing periodic transmissions.The SL DRX information may include the priority of the correspondingPSSCH transmission and/or whether the corresponding PSSCH transmissionis prioritized or not. The corresponding PSSCH transmission may beeither the PSSCH transmission scheduled by the PSCCH or a next PSSCHtransmission reserved by the PSCCH.

The third wireless device informs, via the at least one transceiver, anetwork about the first and second SL DRX information. Each of the firstand second SL DRX information is constructed for each pair of source anddestination.

In some implementations, the first and second SL DRX information may beinformed to the network via a single message. For example, the first andsecond SL DRX information may be informed to the network via a RRCmessage or UCI or MAC CE.

In some implementations, the first and second SL DRX information may beconstructed for each destination, each pair of source/destination and/oreach PC5-RRC connection.

In some implementations, the third wireless device receive DL DRXconfiguration from the network. The third wireless device may receive SLDRX configuration from the network and/or first/second wireless device.Both configurations may not be overlapped in time. The SL DRXconfiguration may be provided for each destination, each pair ofsource/destination and/or each PC5-RRC connection. Thus, the thirdwireless device may receive a list of SL DRX configurations. Each SL DRXconfiguration may be applied to the corresponding destination,corresponding pair of source/destination and/or corresponding PC5-RRCconnection.

In some implementations, the third wireless device may monitor PDCCHaccording to the DL DRX configuration, while monitoring SCIs on PSCCHaccording to the SL DRX configuration. If the SL DRX configuration hasbeen not provided or not included in the list for the correspondingdestination, corresponding pair of source/destination and/orcorresponding PC5-RRC connection, the third wireless device mayconstruct its own SL DRX configuration.

In some implementations, a first SL DRX configuration may be receivedfrom the network and/or the first wireless device, a second SL DRXconfiguration may be received from the second wireless device. The firstSL DRX configuration and the second SL DRX configuration may beconfigured for same destination, same pair of source/destination and/orsame PC5-RRC connection. In this case, the third wireless device maymonitor time durations (i.e., SL active time) according to both thefirst and second SL DRX configurations. For example, if the networkand/or the first other wireless device (e.g., relay UE) provides thefirst SL DRX configuration and the second other wireless device providesthe second SL DRX configuration for the same destination, same pair ofsource/destination and/or same PC5-RRC connection, the third wirelessdevice may monitor time durations (i.e., SL active time) according toboth SL DRX configurations.

For example, a first set of time durations may be determined based onthe first SL DRX configuration. A second set of time durations may bedetermined based on the second SL DRX configuration. Each time durationmay include at least one PSCCH duration. Only time durations overlappedby both the first set of time durations and the second set of timedurations may be monitored. Or, i) time durations overlapped by both thefirst set of time durations and the second set of time durations, andii) either one of the first set of time durations and the second set oftime durations may be monitored. Or, both the first set of timedurations and the second set of time durations may be monitored.

For example, the third wireless device may determine the first set oftime durations according to the first SL DRX configuration and thesecond set of time durations according to the second SL DRXconfiguration. The third wireless device may only monitor time durationsoverlapped by both the first and second sets of time durations. Or, thethird wireless device may monitor the first set of time durations andthe overlapped time durations. Or, the third wireless device may monitorthe second set of time durations and the overlapped time durations. Or,the third wireless device may monitor both the first set and the secondset of time durations. The time duration may be at least PSCCH duration.

In some implementations, the third wireless device may consider thePSCCH duration(s) as a SL active time for sidelink reception from thefirst/second wireless device. If one of the PSCCH durations determinedis overlapped with one of PDCCH durations determined by the DL DRXconfiguration, the overlapped PSCCH duration may not be included in theSL active time. Thus, PSCCH may not be needed to be monitored in theoverlapped PSCCH duration.

In some implementations, the third wireless device may monitor PSCCHtransmission(s) in the active time to receive sidelink transmission fromthe first/second wireless device.

In some implementations, based on deprioritizing sidelink reception,monitoring PSCCH transmission corresponding to the deprioritizedsidelink reception may be skipped. For example, if the network providesDL DRX configuration and the first/second wireless device provides SLDRX configuration, and if sidelink reception is deprioritized due to,e.g., downlink reception, sidelink transmission or uplink transmission,the third wireless device may skip monitoring the PSCCH transmissioncorresponding to the deprioritized sidelink reception.

In some implementations, based on a PSCCH transmission indicating ahigher priority value than a priority value of an overlappedtransmission/reception and/or the PSCCH transmission indicating that acorresponding PSSCH transmission is deprioritized or not prioritized,monitoring the corresponding PSSCH transmission may be skipped. That is,if the PSCCH transmission indicates a higher priority value than thepriority value of an overlapped transmission/reception, and/or if thePSCCH transmission indicates that the corresponding PSSCH transmissionis deprioritized or not prioritized, the third wireless device may skipmonitoring the corresponding PSSCH transmission. The overlappedtransmission/reception may include at least one of a sidelinktransmission, a sidelink reception, a downlink reception and/or anuplink transmission.

In some implementations, information on a duration for the skippedcorresponding PSSCH duration may be informed to a network and/or thefirst wireless device and/or the second wireless device. That is, thethird wireless device may inform the network and/or the first/secondwireless device about the PSCCH duration for the skipped transmission.

Furthermore, the method in perspective of the third wireless devicedescribed above in FIG. 10 may be performed by control of the processor102 included in the first wireless device 100 shown in FIG. 2 , bycontrol of the communication unit 110 and/or the control unit 120included in the wireless device 100 shown in FIG. 3 , and/or by controlof the processor 102 included in the UE 100 shown in FIG. 4 .

More specifically, a processing apparatus operating in a wirelesscommunication system (e.g., third wireless device) comprises at leastone processor, and at least one memory operably connectable to the atleast one processor. The at least one processor is configured to performoperations comprising: establishing at least one first PC5-RRCconnection with a first wireless device for a first pair of source anddestination, establishing at least one second PC5-RRC connection with asecond wireless device for a second pair of source and destination,obtaining first SL DRX information, and obtaining second SL DRXinformation. Each of the first and second SL DRX information isconstructed for each pair of source and destination.

Furthermore, the method in perspective of the third wireless devicedescribed above in FIG. 10 may be performed by a software code 105stored in the memory 104 included in the first wireless device 100 shownin FIG. 2 .

The technical features of the present disclosure may be embodieddirectly in hardware, in a software executed by a processor, or in acombination of the two. For example, a method performed by a wirelessdevice in a wireless communication may be implemented in hardware,software, firmware, or any combination thereof. For example, a softwaremay reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, harddisk, a removable disk, a CD-ROM, or any other storage medium.

Some example of storage medium may be coupled to the processor such thatthe processor can read information from the storage medium. In thealternative, the storage medium may be integral to the processor. Theprocessor and the storage medium may reside in an ASIC. For otherexample, the processor and the storage medium may reside as discretecomponents.

The computer-readable medium may include a tangible and non-transitorycomputer-readable storage medium.

For example, non-transitory computer-readable media may include RAM suchas synchronous dynamic random access memory (SDRAM), ROM, non-volatilerandom access memory (NVRAM), EEPROM, flash memory, magnetic or opticaldata storage media, or any other medium that can be used to storeinstructions or data structures. Non-transitory computer-readable mediamay also include combinations of the above.

In addition, the method described herein may be realized at least inpart by a computer-readable communication medium that carries orcommunicates code in the form of instructions or data structures andthat can be accessed, read, and/or executed by a computer.

According to some implementations of the present disclosure, anon-transitory computer-readable medium (CRM) has stored thereon aplurality of instructions.

More specifically, at least one CRM stores instructions that, based onbeing executed by at least one processor, perform operations comprising:establishing at least one first PC5-RRC connection with a first wirelessdevice for a first pair of source and destination, establishing at leastone second PC5-RRC connection with a second wireless device for a secondpair of source and destination, obtaining first SL DRX information, andobtaining second SL DRX information. Each of the first and second SL DRXinformation is constructed for each pair of source and destination.

FIG. 11 shows an example of a method performed by a network node towhich implementation of the present disclosure is applied.

In step S1100, the method includes transmitting, to a third wirelessdevice, a resource pool configuration.

In step S1100, the method includes receiving, from the third wirelessdevice, first DRX information and second SL DRX information. Each of thefirst and second SL DRX information is constructed for each pair ofsource and destination. The first DRX information is for a first pair ofsource and destination between the third wireless device and a firstwireless device, and the second DRX information is for a second pair ofsource and destination between the third wireless device and a secondwireless device.

In some implementations, the first and second SL DRX information may bereceived via a single message. For example, the first and second SL DRXinformation may be received via a RRC message or UCI or MAC CE.

In some implementations, the first and second SL DRX information may beconstructed for each destination, each pair of source/destination and/oreach PC5-RRC connection.

Furthermore, the method in perspective of the network node describedabove in FIG. 11 may be performed by the second wireless device 200shown in FIG. 2 , and/or the wireless device 100 shown in FIG. 3 .

More specifically, the network node comprises at least one transceiver,at least one processor, and at least one memory operably connectable tothe at least one processor and storing instructions that, based on beingexecuted by the at least one processor, perform operations below.

The network node transmits, to a third wireless device via the at leastone transceiver, a resource pool configuration.

The network node receives, from the third wireless device via the atleast one transceiver, first DRX information and second SL DRXinformation. Each of the first and second SL DRX information isconstructed for each pair of source and destination. The first DRXinformation is for a first pair of source and destination between thethird wireless device and a first wireless device, and the second DRXinformation is for a second pair of source and destination between thethird wireless device and a second wireless device.

In some implementations, the first and second SL DRX information may bereceived via a single message. For example, the first and second SL DRXinformation may be received via a RRC message or UCI or MAC CE.

In some implementations, the first and second SL DRX information may beconstructed for each destination, each pair of source/destination and/oreach PC5-RRC connection.

FIGS. 12 and 13 shows an example of sidelink transmission and sidelinkreception to which implementation of the present disclosure is applied.

First, FIG. 12 is described.

In step S1200, the network may transmit system information includingresource pool configuration to TX UE and RX UE. According to theresource pool configuration, TX UE and RX UE may be configured with oneor more pools of resources.

In step S1202 and S1204, TX UE and RX UE may establish a PC5-RRCconnection with each other for a pair of source and destination. TX UEmay transmit Direct Communication Request to RX UE, and RX UE maytransmit Direct Communication Response to TX UE.

In step S1206, TX UE may select one pool of resources. TX UE may beconfigured with one or more grants such as configured grant(s) ordynamic grant(s) on a particular pool of resources selected by thenetwork for sidelink transmission. The grant may be given by thenetwork.

In step S1208, TX UE may determine SL DRX configuration/information(e.g., the second SL DRX configuration) based on the reserved resourcesand/or the given grants, and send determined SL DRXconfiguration/information to the network.

In some implementations, if the network provides the first SL DRXconfiguration and TX UE determines the second SL DRX configuration forthe same destination, same pair of source/destination and/or samePC5-RRC connection, TX UE may determine time durations (e.g., SL activetime) as the determined SL DRX information according to first and secondSL DRX configurations.

In some implementations, TX UE may determine the first set of timedurations according to the first SL DRX configuration and the second setof time durations according to the second SL DRX configuration. Then, TXUE may only monitor time durations overlapped by both the first andsecond sets of time durations. Alternatively, TX UE may monitor thefirst set of time durations and the overlapped time durations. Or, (ifthe other UE is relay UE) TX UE may monitor the second set of timedurations and the overlapped time durations. Or, (if the other UE isrelay UE) TX UE may monitor both the first set and the second set oftime durations. The time duration may be at least PSCCH duration.

In some implementations, TX UE may indicate the determined SL DRXinformation on the selected pool of resources to the network. The SL DRXinformation may be transmitted to the network via a RRC message or UCIor MAC CE. The SL DRX information may be constructed for eachdestination, each pair of source/destination and/or each PC5-RRCconnection. The SL DRX information may include PSCCH duration(s) for oneor more next transmissions from TX UE performing periodic transmissions.The SL DRX information may include the priority of corresponding PSSCHtransmission and/or whether the corresponding PSSCH transmission isprioritized or not. The corresponding PSSCH transmission may be eitherthe PSSCH transmission scheduled by the PSCCH and/or a next PSSCHtransmission reserved by the PSCCH.

In step S1210, TX UE may receive RRC reconfiguration message includingDL DRX configuration and/or SL DRX configuration from the network.

In step S1212, TX UE may receive a configured grant activation from thenetwork.

In step S1214, TX UE may determine SL DRX configuration/informationbased on the reserved resources or the given grants and send thedetermined SL DRX configuration/information to RX UE. TX UE may indicatethe SL DRX configuration/information on the selected pool of resourcesto RX UE.

In some implementations, the SL DRX information may be transmitted to RXUE via 1st stage SCI on PSCCH, 2nd stage SCI on PSSCH or a MAC CE onPSSCH. In some implementations, the SL DRX information may include PSCCHduration(s) for one or more next transmissions from TX UE performingperiodic transmissions. In some implementations, the SL DRX informationmay include the priority of corresponding PSSCH transmission and/or thewhether the corresponding PSSCH transmission is prioritized or not. Thecorresponding PSSCH transmission may be either the PSSCH transmissionscheduled by the PSCCH and/or a next PSSCH transmission reserved by thePSCCH.

In step S1216, RX UE may inform the network about the received SL DRXinformation.

In some implementations, the SL DRX information may be transmitted tothe network via a RRC message or UCI or MAC CE. The SL DRX informationmay be constructed for each destination, each pair of source/destinationand/or each PC5-RRC connection.

In step 1218, RX UE may receive DL DRX configuration from the network.RX UE may receive SL DRX configuration from the network (and/or from TXUE). Both configurations may not be overlapped in time.

In some implementations, the SL DRX configuration may be provided foreach destination, each pair of source/destination and/or each PC5-RRCconnection. Thus, RX UE may receive a list of SL DRX configurations.Each SL DRX configuration may be applied to the correspondingdestination, corresponding pair of source/destination and/orcorresponding PC5-RRC connection.

In step S1220, RX UE may monitor PDCCH according to the DL DRXconfiguration while monitors SCIs on PSCCH according to the SL DRXconfiguration. The time duration may be at least PSCCH duration.

In some implementations, if a SL DRX configuration has been not providedor not included in the list for the corresponding destination,corresponding pair of source/destination and/or corresponding PC5-RRCconnection, RX UE may construct its own SL DRX configuration.

In some implementations, if the network and/or the first other UE (e.g.,relay UE) provides the first SL DRX configuration and the second otherUE provides the second SL DRX configuration for the same destination,same pair of source/destination and/or same PC5-RRC connection, RX UEmay monitor time durations (i.e., SL active time) according to both SLDRX configurations. For example, TX UE may determine the first set oftime durations according to the first SL DRX configuration and thesecond set of time durations according to the second SL DRXconfiguration. Then, RX UE may only monitor time durations overlapped byboth the first and second sets of time durations. Alternatively, RX UEmay monitor the first set of time durations and the overlapped timedurations. Or, RX UE may monitor the second set of time durations andthe overlapped time durations. Or, RX UE may monitor both the first setand the second set of time durations.

Now, FIG. 13 whose operation follows the operation of FIG. 12 isdescribed.

In step S1300, TX UE may perform sidelink transmission to RX UE by usingone of the reserved resources.

In step S1302, RX UE may consider the PSCCH duration(s) as a SL activetime for sidelink reception from TX UE. RX UE may monitor PSCCHtransmission(s) in the SL active time to receive sidelink transmissionfrom TX UE.

In step S1304, TX UE may perform sidelink transmission to RX UE by usingone of the reserved resources.

In step S1306, if RX UE deprioritizes sidelink reception due to e.g.,prioritized downlink reception, prioritized sidelink transmission,prioritized sidelink reception from other UE, or prioritized uplinktransmission, RX UE may skip monitoring the PSCCH transmissioncorresponding to the deprioritized sidelink reception.

For example, if one of the PSCCH durations determined is overlapped withone of PDCCH durations determined by the DL DRX configuration, theoverlapped PSCCH duration may not be included in the SL active time.Thus, RX UE may not monitor PSCCH in the overlapped PSCCH duration.

For example, if the network indicates a lower priority value of thedownlink transmission than a threshold, RX UE may prioritize thedownlink transmission. The priority value may be indicated by PDCCHallocating downlink transmission resource or RRC.

For example, if the network indicates a lower priority value of theuplink transmission than a threshold, RX UE may prioritize the uplinktransmission. The priority value may be indicated by PDCCH allocatinguplink transmission resource or RRC.

For example, if the value of the highest priority of a MAC PDU for theuplink transmission is lower than a threshold, RX UE may prioritize theuplink transmission. The priority value may be indicated by PDCCHallocating uplink transmission resource or RRC.

For example, if the value of the highest priority of a MAC PDU for thesidelink transmission is lower than a threshold and/or the priorityvalue of the sidelink reception, RX UE may prioritize the sidelinktransmission. The priority value of the sidelink reception may beindicated by SCI.

For example, if the value of the highest priority of a MAC PDU for thesidelink reception is lower than a threshold and/or the priority valueof the sidelink transmission, RX UE may prioritize the sidelinkreception. The priority value of the sidelink reception may be indicatedby SCI.

In step S1308, RX UE may receive PDCCH/PDSCH transmission from thenetwork.

In step S1310, RX UE may receive sidelink transmission from TX UE byusing one of the reserved resources.

In step S1312, RX UE may inform the network (and/or TX UE) about updatedSL DRX information including the PSCCH duration for the skippedtransmission.

The present disclosure can have various advantageous effects.

For example, DL DRX and SL DRX can be aligned by enabling UE performingSL transmission/reception to report SL DRX information of other UE tothe network.

For example, UE performing reception on a pool of resources can save UEpower, in particular when UE receive multiple DRX configurations fromother UE(s) and/or the network.

For example, the system can properly provide power-efficient sidelinkreception based on multiple DRX configurations and prioritization.

Advantageous effects which can be obtained through specific embodimentsof the present disclosure are not limited to the advantageous effectslisted above. For example, there may be a variety of technical effectsthat a person having ordinary skill in the related art can understandand/or derive from the present disclosure. Accordingly, the specificeffects of the present disclosure are not limited to those explicitlydescribed herein, but may include various effects that may be understoodor derived from the technical features of the present disclosure.

Claims in the present disclosure can be combined in a various way. Forinstance, technical features in method claims of the present disclosurecan be combined to be implemented or performed in an apparatus, andtechnical features in apparatus claims can be combined to be implementedor performed in a method. Further, technical features in method claim(s)and apparatus claim(s) can be combined to be implemented or performed inan apparatus. Further, technical features in method claim(s) andapparatus claim(s) can be combined to be implemented or performed in amethod. Other implementations are within the scope of the followingclaims.

1-18. (canceled)
 19. A method performed by a User Equipment (UE) adaptedto operate in a wireless communication system, the method comprising:establishing a PC5-Radio Resource Control (RRC) connection with at leastone peer UE, wherein the PC5-RRC connection is a logical connectionbetween the UE and the at least one peer UE for a pair of Source Layer-2Identity (ID) and Destination Layer-2 ID, and wherein the UE isconfigured to perform sidelink reception; receiving a Sidelink (SL)Discontinuous Reception (DRX) configuration for sidelink reception fromthe at least one peer UE; and initiating transmission of an RRC messageto report the SL DRX configuration, wherein the SL DRX configuration isset for each destination in the RRC message.
 20. The method of claim 19,wherein the sidelink reception corresponds to a New Radio (NR) sidelinkunicast reception.
 21. The method of claim 19, wherein the at least onepeer UE comprises a first peer UE and a second peer UE.
 22. The methodof claim 21, wherein a first PC5-RRC connection is established betweenthe UE and the first peer UE for a first pair of Source Layer-2 ID andDestination Layer-2 ID, and wherein a second PC5-RRC connection isestablished between the UE and the second peer UE for a second pair ofSource Layer-2 ID and Destination Layer-2 ID.
 23. The method of claim22, wherein a first SL DRX configuration is received from the first peerUE, and wherein a second SL DRX configuration is received from thesecond peer UE.
 24. The method of claim 23, wherein the first SL DRXconfiguration is determined by the first peer UE, and wherein the secondSL DRX configuration is determined by the second peer UE.
 25. The methodof claim 23, wherein a first set of time durations is determined basedon the first SL DRX configuration, wherein a second set of timedurations is determined based on the second SL DRX configuration, andwherein each time duration includes at least one Physical SidelinkControl Channel (PSCCH) duration.
 26. The method of claim 19, wherein,based on deprioritizing the sidelink reception, monitoring PSCCHtransmission related to the deprioritized sidelink reception is skipped.27. The method of claim 19, wherein, based on a PSCCH transmissionindicating a higher priority value than a priority value of anoverlapped transmission and/or the PSCCH transmission indicating that acorresponding Physical Sidelink Shared Channel (PSSCH) transmission isdeprioritized or not prioritized, monitoring the corresponding PSSCHtransmission is skipped.
 28. A User Equipment (UE) adapted to operate ina wireless communication system, the UE comprising: at least onetransceiver; at least one processor; and at least one memory operablyconnectable to the at least one processor and storing instructions that,based on being executed by the at least one processor, performoperations comprising: establishing a PC5-Radio Resource Control (RRC)connection with at least one peer UE, wherein the PC5-RRC connection isa logical connection between the UE and the at least one peer UE for apair of Source Layer-2 Identity (ID) and Destination Layer-2 ID, andwherein the UE is configured to perform sidelink reception; receiving,via the at least one transceiver, a Sidelink (SL) DiscontinuousReception (DRX) configuration for sidelink reception from the at leastone peer UE; and initiating transmission of an RRC message, via the atleast one transceiver, to report the SL DRX configuration, wherein theSL DRX configuration is set for each destination in the RRC message. 29.The UE of claim 28, wherein the sidelink reception corresponds to a NewRadio (NR) sidelink unicast reception.
 30. The UE of claim 28, whereinthe at least one peer UE comprises a first peer UE and a second peer UE.31. The UE of claim 30, wherein a first PC5-RRC connection isestablished between the UE and the first peer UE for a first pair ofSource Layer-2 ID and Destination Layer-2 ID, and wherein a secondPC5-RRC connection is established between the UE and the second peer UEfor a second pair of Source Layer-2 ID and Destination Layer-2 ID. 32.The UE of claim 31, wherein a first SL DRX configuration is receivedfrom the first peer UE, and wherein a second SL DRX configuration isreceived from the second peer UE.
 33. The UE of claim 32, wherein thefirst SL DRX configuration is determined by the first peer UE, andwherein the second SL DRX configuration is determined by the second peerUE.
 34. The UE of claim 32, wherein a first set of time durations isdetermined based on the first SL DRX configuration, wherein a second setof time durations is determined based on the second SL DRXconfiguration, and wherein each time duration includes at least onePhysical Sidelink Control Channel (PSCCH) duration.
 35. The UE of claim28, wherein, based on deprioritizing the sidelink reception, monitoringPSCCH transmission related to the deprioritized sidelink reception isskipped.
 36. The UE of claim 28, wherein, based on a PSCCH transmissionindicating a higher priority value than a priority value of anoverlapped transmission and/or the PSCCH transmission indicating that acorresponding Physical Sidelink Shared Channel (PSSCH) transmission isdeprioritized or not prioritized, monitoring the corresponding PSSCHtransmission is skipped.
 37. A processing apparatus adapted to control aUser Equipment (UE) in a wireless communication system, the processingapparatus comprising: at least one processor; and at least one memoryoperably connectable to the at least one processor, wherein the at leastone processor is adapted to perform operations comprising: establishinga PC5-Radio Resource Control (RRC) connection with at least one peer UE,wherein the PC5-RRC connection is a logical connection between the UEand the at least one peer UE for a pair of Source Layer-2 Identity (ID)and Destination Layer-2 ID, and wherein the UE is configured to performsidelink reception; obtaining a Sidelink (SL) Discontinuous Reception(DRX) configuration for sidelink reception; and initiating transmissionof an RRC message to report the SL DRX configuration, wherein the SL DRXconfiguration is set for each destination in the RRC message.